Celebrate a hero of the construction world as you build a replica version of the biggest Cat dozer with this LEGO Technic App-Controlled Cat D11 Bulldozer (42131) kit. This large set lets adults enjoy quality me time focusing on their passion. Just like the real Cat bulldozer, this model is built in modular sections. LEGO fans will love the new-for-October-2021 LEGO element a large track that can be tightened and loosened. And the build is just the start! With many authentic features and functions packed into this model, theres lots to discover. Take control of your bulldozer model Use the CONTROL+ app to operate and explore this heavy-duty machine. Use the app to drive and steer. The app delivers realistic movement as you raise, lower and tilt the blade or raise and lower the ripper and ladder. Explore engineering LEGO Technic buildable models feature realistic movement and mechanisms that let LEGO builders explore engineering concepts in an approachable and realistic way.
Celebrate a hero of the construction world as you build a replica version of the biggest Cat dozer with this LEGO Technic App-Controlled Cat D11 Bulldozer (42131) kit. This large set lets adults enjoy quality me time focusing on their passion. Just like the real Cat bulldozer, this model is built in modular sections. LEGO fans will love the new-for-October-2021 LEGO element a large track that can be tightened and loosened. And the build is just the start! With many authentic features and functions packed into this model, theres lots to discover. Take control of your bulldozer model Use the CONTROL+ app to operate and explore this heavy-duty machine. Use the app to drive and steer. The app delivers realistic movement as you raise, lower and tilt the blade or raise and lower the ripper and ladder. Explore engineering LEGO Technic buildable models feature realistic movement and mechanisms that let LEGO builders explore engineering concepts in an approachable and realistic way.
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The lowest price for LEGO Technic App-Controlled Cat D11 Bulldozer 42131 (3,854 Pieces) right now is $952.44 at eBay.com.au, compared across 2 retailers.
The all-time low was $952.44 on 5 Oct 2026. That's the lowest price we've ever tracked — a great time to buy.
Prices last updated 5 Oct 2026.
LEGO Technic App-Controlled Cat D11 Bulldozer 42131 (3,854 Pieces)
Celebrate a hero of the construction world as you build a replica version of the biggest Cat dozer with this LEGO Technic App-Controlled Cat D11 Bulldozer (42131) kit. This large set lets adults enjoy quality me time focusing on their passion. Just like the real Cat bulldozer, this model is built in modular sections. LEGO fans will love the new-for-October-2021 LEGO element a large track that can be tightened and loosened. And the build is just the start! With many authentic features and functions packed into this model, theres lots to discover. Take control of your bulldozer model Use the CONTROL+ app to operate and explore this heavy-duty machine. Use the app to drive and steer. The app delivers realistic movement as you raise, lower and tilt the blade or raise and lower the ripper and ladder. Explore engineering LEGO Technic buildable models feature realistic movement and mechanisms that let LEGO builders explore engineering concepts in an approachable and realistic way.
Celebrate a hero of the construction world as you build a replica version of the biggest Cat dozer with this LEGO Technic App-Controlled Cat D11 Bulldozer (42131) kit. This large set lets adults enjoy quality me time focusing on their passion. Just like the real Cat bulldozer, this model is built in modular sections. LEGO fans will love the new-for-October-2021 LEGO element a large track that can be tightened and loosened. And the build is just the start! With many authentic features and functions packed into this model, theres lots to discover. Take control of your bulldozer model Use the CONTROL+ app to operate and explore this heavy-duty machine. Use the app to drive and steer. The app delivers realistic movement as you raise, lower and tilt the blade or raise and lower the ripper and ladder. Explore engineering LEGO Technic buildable models feature realistic movement and mechanisms that let LEGO builders explore engineering concepts in an approachable and realistic way.
Last updated at 05/10/2026 16:48:14
LEGO 42131 Technic App-Controlled Cat D11 Bulldozer, Model Building Set for Adults, Remote Control Construction Motor Vehicle
Delivery $49.99
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
LEGO 42131 TECHNI App-Controlled Cat D11 Bulldozer Finished Product
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
originally posted on LEGO
I am 75 years old and haven’t build any Lego since my children were kids, 50 years ago. My wife bought me the Bugatti Chiron for our last wedding anniversary and I became hooked. I bought the CAT bulldozer a month ago and I thought the Bugatti was difficult but the CAT is on a whole different level. The detail is amazing and the remote control app is superb. It needs a great deal of concentration during the build because the detailed instructions have to be followed precisely, one small piece fitted incorrectly will effect the working of the final model but the sense of achievement when I switched the model on and everything worked successfully was tremendous. One word of advice, don’t rush your build, take your time and enjoy putting every piece together.
originally posted on gameofbricks.eu
As is common from Game of Bricks, all the light kits I have purchased are excellent.Good quality parts. Excellent packaging and axceptional value for money.Sometimes the instructions seem daunting but if the look at them thoroughly you will be able to work it out. Plus there is always their customer services who are brilliant to talk to. I have spoken to several of the team and they are polite and knowledgeable.
originally posted on LEGO
First and upmost no missing parts! Excellent kit! I enjoy building big kits with lots of parts and operating gizmos. This is one of those! Realistic, lots of gears and intricate building sequence's. Took my time to build it and enjoyed every minute of it. Having built the Liebherr 9800 and the Off Road Crane 42082, this adds to my small collection of complex kits. If anything I would change would be the color of the threads: grey would have looked more realistic. The Iphone app is a little bit difficult to use and confusing at times. Overall it was a very satisfying building experience, a great build and can not wait for the next huge kit to come out.
| Educational Objective(s) | Engineering Skills |
| Number of pieces | 3854 |
| Assembly Required | No |
| Material Type(s) | Plastic |
| Release date | 1 October 2021 |
LEGO 42131 Technic App-Controlled Cat D11 Bulldozer, Model Building Set for Adults, Remote Control Construction Motor Vehicle
Delivery $49.99
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
LEGO 42131 TECHNI App-Controlled Cat D11 Bulldozer Finished Product
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
I am 75 years old and haven’t build any Lego since my children were kids, 50 years ago. My wife bought me the Bugatti Chiron for our last wedding anniversary and I became hooked. I bought the CAT bulldozer a month ago and I thought the Bugatti was difficult but the CAT is on a whole different level. The detail is amazing and the remote control app is superb. It needs a great deal of concentration during the build because the detailed instructions have to be followed precisely, one small piece fitted incorrectly will effect the working of the final model but the sense of achievement when I switched the model on and everything worked successfully was tremendous. One word of advice, don’t rush your build, take your time and enjoy putting every piece together.
As is common from Game of Bricks, all the light kits I have purchased are excellent.Good quality parts. Excellent packaging and axceptional value for money.Sometimes the instructions seem daunting but if the look at them thoroughly you will be able to work it out. Plus there is always their customer services who are brilliant to talk to. I have spoken to several of the team and they are polite and knowledgeable.
First and upmost no missing parts! Excellent kit! I enjoy building big kits with lots of parts and operating gizmos. This is one of those! Realistic, lots of gears and intricate building sequence's. Took my time to build it and enjoyed every minute of it. Having built the Liebherr 9800 and the Off Road Crane 42082, this adds to my small collection of complex kits. If anything I would change would be the color of the threads: grey would have looked more realistic. The Iphone app is a little bit difficult to use and confusing at times. Overall it was a very satisfying building experience, a great build and can not wait for the next huge kit to come out.
Having build a lot of Technic lego this is in a different class. Full credit must go to the designer as it is beyond me how someone can design such a complex bit of kit. This is certainly not for the beginner and is quite a challenge even for an experienced builder. There is a constant worry that if you make a small mistake early on it could take hours to solve. The automatic test procedure half way through helps to reassure you that so far all is OK. The bluetooth software is magnificent but remember to turn the sound on your phone on as you miss a lot as I did to start with. Well done Lego what tremendous value for money and hours of enjoyment in the build
The overall building process was fun and varied, there’s lots of cool gearing and a few newer pieces as well as the new wide tracks.The price is on the higher side for a large motorized set, at least compared to others like the 42100 liebherr excavator or the 42114 volvo 6x6.The play is ok but clunky. Switching in between any of the non-driving actions takes several seconds (as I understand it, it’s to reduce tension on the gearbox by wiggling the motors) and also means that only one action can be done at once (not including driving). A little disappointing.Overall, it’s a great building experience and looks fantastic as a display, but functionally and price-wise it’s slightly lackluster.
I just finished my build and enjoyed the 8 different modules as they were broken up just like the real dozer. The attention to detail lead to some of the connections being challenging to complete while trying to line up several pins or moving arms simultaneously, could have used a third hand a couple times. The pinned connections often required some pressure to connect when a large number of pins were used together. The operation of the dozer is fun and moves quite well for being such a large build.Where they could have improved is by breaking up the modules a little further, some modules had a large number of pieces to sort through and were typically used in different phases on construction. Breaking these out could have lead to less pieces per module without ... MoreI just finished my build and enjoyed the 8 different modules as they were broken up just like the real dozer. The attention to detail lead to some of the connections being challenging to complete while trying to line up several pins or moving arms simultaneously, could have used a third hand a couple times. The pinned connections often required some pressure to connect when a large number of pins were used together. The operation of the dozer is fun and moves quite well for being such a large build.Where they could have improved is by breaking up the modules a little further, some modules had a large number of pieces to sort through and were typically used in different phases on construction. Breaking these out could have lead to less pieces per module without searching for pieces. The large modules took between 1.5-2 hours each. By comparison the rough terrain crane had nearly double the number of modules for a similar piece count and were closer to 1-1.5 hours each.As someone in the heavy civil construction industry this set was a must have but the price could have been slightly better. Again referencing the rough terrain crane at nearly the same piece count for less than half the cost.
I'd previously built the Technic Lamborghini, and while I enjoyed it, wasn't especially looking forward to my next Technic build. However, I kept seeing the Bulldozer and after watching some videos demonstrating its functionality, I decided to spring for it. I took my time (~ 25-30 hours) spread out over two weeks, being sure all the pieces were correctly in place. The moment of truth was last night, when I finished the build and fired up the app to really test things out. The result? Wow...I am now an absolute Technic fan, and - as I write this - the postman is just delivering the Bugatti! Can't wait to get started on that, and of course looking forward to the Ferrari.
If you love large toys, I highly recommend this build. It's a Great build project, not only because of the high piece count, but because it's so involved. Great job, and kudos to the engineers on the design. It is so realistic. I also love that you can control this unit from an app. Many hours of family fun in your future. I do however have a small gripe. 1) How can Lego put out an item like this and not include a construction guy with a helmet...... Lol, and 2) why doesn't this unit also include one of those small tools to dismantle the unit . Thanks for the fun times, Lego.
Right out of the box there has been a problem with the build. Stage one went as planned but when I got to stage two there was an entire package of parts missing. I've build several of Lego's high end kits and this is the first time that any parts have been missing. With a build as complicated as the D-11 Cat, missing over 125 pieces from an early stage is a stopping block. I have to say that Lego was on the ball and sent the missing pack out within 48 hours. It's been over a week and the parts aren't here yet. At this point I am considering sending it back. If you are looking for a build that will tax your abilities, this is it. It's huge and heavy. I'm a little concerned about the track but we'll see if I decide to keep it after the missing parts are here. I'' let ... MoreRight out of the box there has been a problem with the build. Stage one went as planned but when I got to stage two there was an entire package of parts missing. I've build several of Lego's high end kits and this is the first time that any parts have been missing. With a build as complicated as the D-11 Cat, missing over 125 pieces from an early stage is a stopping block. I have to say that Lego was on the ball and sent the missing pack out within 48 hours. It's been over a week and the parts aren't here yet. At this point I am considering sending it back. If you are looking for a build that will tax your abilities, this is it. It's huge and heavy. I'm a little concerned about the track but we'll see if I decide to keep it after the missing parts are here. I'' let you know. *Update; I have decided to return this item. It has nothing to do with LEGO. It is the fact that the replacement parts haven't arrived yet and even if they arrive today, I don't have time to assemble it by Christmas. I will continue to but LEGO products. Merry Christmas everyone.
The bulldozer itself is an amazing set. I thoroughly enjoyed building it and did not have a difficult time. In other sets, I have had trouble with pieces getting knocked off as I build, but this set was better. I also appreciate Lego and their customer support to help with missing pieces. Outstanding service.However, I am thoroughly DISSAPPOINTED in the app controller.1. You can't test the set until it is Fully assembled because the app wants to calibrate ALL the movements of the completed set. If you find an error after the set is built, you cannot reach the gearing areas where there is an issue. Your choice is disassemble the set or leave it dead.2. If one action does not work, the calibration will not be completed. For example, in my case, the side ladder did ... MoreThe bulldozer itself is an amazing set. I thoroughly enjoyed building it and did not have a difficult time. In other sets, I have had trouble with pieces getting knocked off as I build, but this set was better. I also appreciate Lego and their customer support to help with missing pieces. Outstanding service.However, I am thoroughly DISSAPPOINTED in the app controller.1. You can't test the set until it is Fully assembled because the app wants to calibrate ALL the movements of the completed set. If you find an error after the set is built, you cannot reach the gearing areas where there is an issue. Your choice is disassemble the set or leave it dead.2. If one action does not work, the calibration will not be completed. For example, in my case, the side ladder did not move in calibration. Therefore, the app could not finish the calibration process and now the bulldozer sits on the desk unable to move. I could care less if the ladder moves or not, but let me play with the rest of the features. Don't make the app and All-or-Nothing controller.3. During calibration, the range of motion is excessive. In my set, the calibration started and moved the assembly in one direction. When it reached max, I would expect to hear a couple clicks of the gear as it maxes out. But nope, I heard click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click. That can't be good for the motors or the gears. I don't know why it needed to be pushed that hard during calibration.4. The calibration would sometimes stop working at the end of certain steps and needed to be restarted. In my set, after the first motion was calibrated, I would just see the icon on the app rotating endlessly (like the spinning hourglass that resulted in nothing). There was no indication from the app on what was wrong or what needed to be done. Just a spinning icon and a Lego set laying dead on my desk. I had to go back and restart the calibration process again, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click, click,My recommendations1. Lego should rebuild the app so it is better and more accommodating.2. Add the ability to test assembly motions with the controller in earlier stages. Add notes in the instruction manual to indicate; test here to expect to see xyz.
| Educational Objective(s) | Engineering Skills |
| Number of pieces | 3854 |
| Assembly Required | No |
| Material Type(s) | Plastic |
| Release date | 1 October 2021 |
